Enhancement : Attach images to post uploaded in core/image block via media library

[Vrishabhsk]

What?

• Closes : Image Block: When adding an existing image within a post, explore "attaching" the image to the post if it isn't already attached #66663
• Attach image to post that is uploaded in core/image block via media library option.
• Detach the image when the block is removed or the reset option is selected.

Why?

• Image Block: When adding an existing image within a post, explore "attaching" the image to the post if it isn't already attached #66663
• Images are not attached to the post when they are added via the media library option in the core/image block.
• The attachment only happens when the image is uploaded while the user is in editing a post.

How?

• Evaluate if the attachment is already attached to another post via its uploadedTo media parameter
• If not attached, when the post is saved / published the image will be attached to the post where its used.
• When either the reset option in the core/image block is selected or the block is removed, the image is detached from the post.
• The attachment/detachment process works via the WP REST API for attachments

Testing Instructions

1. Add dummy images in the media library of your WP installation.
2. Create a post and add an image block to it.
3. Select the image via media library option.
4. Save/Publish the post and go back to the media library.
5. You will see the image attached to that post.
6. If you remove the block or click the reset option in the core/image block, the image will be detached from the post.

Testing Instructions for Keyboard

Screenshots or screencast

new-feature.mp4

[github-actions]

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Co-authored-by: Vrishabhsk <vrishabhsk@git.wordpress.org>
Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>
Co-authored-by: Marc-pi <mdxfr@git.wordpress.org>
Co-authored-by: ellatrix <ellatrix@git.wordpress.org>
Co-authored-by: andrewserong <andrewserong@git.wordpress.org>

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[Mamaduka]

The editor package cannot be a dependency for block-library. Only packages that depend on it are edit-site and edit-post.

[Mamaduka]

I believe something similar was resolved a couple of releases ago. The fix should be more general to the upload handler, instead of the Image block.

Core has more blocks that can upload and use images.

[Vrishabhsk]

Thanks for the review @Mamaduka, ill look for the blocks that have the media library handling and generalize this feature.

[Mamaduka]

Thanks, @Vrishabhsk!

[Mamaduka]

@Vrishabhsk, let's close this PR, since you're planning to explore an alternative solution.